Paul Smith wrote:
I believe that the problem has to do with the understanding of variables. If we take those student responses at face value, the students are showing that they don't know the difference between a group of people and a variable (a conclusion supported by the fact that when asked what their independent variable is, students often reply "The independent variable was the people who got the treatment"). Now, students obviously know what a group of people is, and that's a concrete thing. I think it's the abstract nature of variables that gets in their way. That's reinforced by the fact that so many people say things like "you can't measure (X)" (where X is some non-physical variable like "ambition", or "drive" or "love") or "Human beings are complex: you can't separate out the effect of X on their behavior from all the other things that affect behavior".
I agree that many students have great difficulty understanding the definition of both independent and dependent variables.
I wonder if part of the problem is due to the way experiments are often described in courses other than research methods. Here is a slightly exaggerated description of an experiment that I hear people use,
"So Smith and Steele were interested in the question of whether caffeine improves memory. The IV was caffeine and the DV was number of trials to learn a list of words to a 90% criterion. The experimental group received 300 mg of caffeine. The results showed that the experimental group learned the list in significantly fewer trails."
Notice how much emphasis there is on the treatment of interest and how little is said about the role of the control group or the point that it is the difference between the groups that we are evaluating.
This tendency to focus on the experimental treatment in our descriptions may contribute to the confusion of an IV with a specific condition.
Ken
Paul Smith Alverno College Milwaukee
-- --------------------------------------------------------------- Kenneth M. Steele, Ph.D. [EMAIL PROTECTED] Department of Psychology http://www.psych.appstate.edu Appalachian State University Boone, NC 28608 USA --------------------------------------------------------------- --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english
